Catheter with removable balloon protector and stent delivery system with removable stent protector

ABSTRACT

A balloon catheter is provided having an expandable distal portion and balloon protector means comprising a first removable sleeve having a variable inner diameter to ease sliding the first sleeve over the balloon, and an optional second removable (outer) sleeve positioned over the inner sleeve, the second (outer) sleeve having a constrictive relationship with the first (inner) sleeve, said first and second sleeves being removed prior to use of the catheter. A stent delivery system is provided to facilitate introduction and placement of a stent, and includes a catheter having an expandable distal portion constructed and arranged for expanding the outer diameter of the catheter from a contracted state to an expanded state, said distal portion further comprising a balloon and at least one dam over which the balloon extends, and a stent positioned around the distal portion of the catheter around the balloon or gripper linear control device, said stent having a contracted condition, being sized in the contracted condition to closely surround the balloon in the contracted state, and being expandable to an expanded condition; a first removable (inner) sleeve in the region of the distal portion of the catheter positioned around the stent (and between the damns where the device comprises two dams), said first sleeve comprising a first end, a second end and a variable inner diameter to ease sliding the sleeve over the balloon and stent; an optional second removable (outer) sleeve positioned over the stent, first sleeve and at least one dam, said second (outer) sleeve having a constrictive relationship with the first (inner) sleeve, whereby when compressed by the outer sleeve, the inner sleeve will have an inner diameter approximately equal to or less than the outer profile of the collapsed balloon over the at least one dam, said first and second sleeves being removed prior to use of the stent delivery system and release of the stent by expansion of the balloon.

CROSS REFERENCE TO RELATED APPLICATIONS

This Application is a divisional application of Application 09/034,434,filed Mar. 4, 1998, now U.S. Pat. No. 6,152,944, which is aContinuation-in-part of U.S. patent application Ser. No. 08/812,351,filed Mar. 5, 1997, now U.S. Pat. No. 5,893,868.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to catheters having anexpandable balloon and to premounted balloon expandable stent ballooncatheters, and specifically to a dilatation balloon catheter with aballoon protector means or a stent delivery system with a balloon andstent protector means.

2. Description of Related Art

Percutaneous transluminal coronary ingioplasty (PTCA) is a procedurewhich is well established for the treatment of blockages in the coronaryarteries. Blockages may occur from cholesterol precipitation on thecoronary wall which may be in any stage from initial deposit throughaged lesions. Coronary arteries may also become blocked due to formationof thrombus.

The most widely used form of percutaneous coronary angioplasty makes useof a dilatation balloon catheter. In typical PTCA procedures, thecardiovascular system of a patient is accessed with an introducer,usually in the groin area. All other devices including a guidingcatheter are percutaneously introduced into the cardiovascular system ofa patient through the introducer and advanced through a vessel until thedistal end thereof is at a desired location in the vasculature. A guidewire and a dilatation catheter having a balloon on the distal endthereof are introduced through the guiding catheter with the guide wiresliding through the dilatation catheter. The guide wire is firstadvanced out of the guiding catheter into the patienit's coronaryvasculature and the dilatation catheter is advanced over the previouslyadvanced guide wire until the dilatation balloon is properly positionedacross the lesion. Once in position across the lesion, the flexible,expandable, preformed balloon is inflated to a predetermined size with afluid at relatively high pressures, such as greater than about fouratmospheres, to radially compress the atherosclerotic plaque of thelesion against the inside of the artery wall and thereby dilate thelumen of the artery. The balloon is then deflated to a small profile sothat the dilatation catheter may be withdrawn from the patientsvasculature and blood flow resumed through the dilated artery.

In angioplasty procedures of the kind described above, there may berestenosis of the artery, which either necessitates another angioplastyprocedure, a surgical by-pass operation, or some method of repairing orstrengthening the area. To reduce restenosis and strengthen the area, aphysician can implant an intravascular prosthesis for maintainingvascular patency, called a stent, inside the artery at the lesion. Ingeneral, stents are prosthetic devices which can be positioned within abody cavity, for example, a blood vessel of the body of a living humanor in some other difficulty accessible place. A stent generally has adiameter which may be increased or decreased. Stents are particularlyuseful for permanently widening a vessel which is in a narrowed state,or for internally supporting a vessel damaged by an aneurysm.

Such stents are typically introduced into the body cavity by use of acatheter. The catheter is usually of the balloon catheter type in whichthe balloon is utilized to expand the stent, which is positioned overthe balloon, to place it in a selected location in the body cavity. Thestent is expanded to a larger diameter for placement in the vasculature,often by the balloon portion of the catheter. Stents delivered to arestricted coronary artery, expanded to a larger diameter by a ballooncatheter, and left in place in the artery at the site of a dilatedlesion are shown in U.S. Pat. No. 4,740,207 to Kreamer and U.S. Pat. No.5,007,926 to Derbyshire.

One important characteristic of a dilatation balloon catheter is its“profile”, which is determined by the outer diameter (O.D.) of thedistal end portion of the balloon and stent when deflated. The outerdiameter affects the ease and ability of the dilatation catheter to passthrough a guide catheter, through the coronary arteries, and across atight lesion. Considerable effort has been made in developing lowprofile dilatation balloon catheters. U.S. Pat. No. 5,342,307,incorporated herein by reference, discloses a balloon protector sleeveused with a tri-fold dilatation balloon catheter for angioplasty.

Minimization of “profile” is of importance in balloon catheters andstent delivery systems. Accordingly, the present invention isparticularly directed to improved arrangements of balloon cathetershaving a balloon protector and stent delivery systems having a balloonand including a stent protector means which provide a minimized profile.

SUMMARY OF THE INVENTION

This invention concerns medical devices such as balloon catheters andapparatus suitable for delivery of stents to body cavities. The presentinvention is particularly directed to improved balloon protectors foruse with balloon catheters and to improved arrangements for stentdelivery systems, the improvements comprising stent protector means.

Accordingly, the present invention provides a catheter having anexpandable distal portion constructed and arranged for expanding theouter diameter of the catheter from a contracted state to an expandedstate. The distal portion of the catheter comprises a balloon which isfolded or otherwise collapsed, and is expandable to an expandedcondition. The balloon protector may comprise removable first and secondsleeves. The first removable (inner) sleeve is positioned around theballoon, the inner sleeve being made of a lubricious material andfurther comprising a first end, a second end and a slit extendingtherethrough. The slit may extend from end to end. Alternatively, theslit may extend along a predetermined length of the sleeve, the rest ofthe length of the sleeve comprising a continuous tube. The slit providesa variable inner diameter to ease sliding the sleeve over the balloon.The second removable (outer) sleeve is positioned over the first (inner)sleeve, the outer sleeve having a constrictive relationship with theinner sleeve. The outer sleeve thereby provides an additionalcompressive force to reduce the profile of the constricted balloon. Forexample, the outer sleeve may have an inner diameter less than the outerdiameter of the inner sleeve, whereby when compressed by the outersleeve, the inner sleeve will have an inner diameter approximately equalto or greater than the profile of the balloon in its contracted state.The inner and outer sleeves are removed prior to use of the catheter.

Alternatively, the balloon protector means may comprise a singlecompressive sleeve. This single compressive sleeve may be of anyconfiguration described herein. A preferred embodiment of the singlesleeve has a slit along the length thereof. Another preferred embodimentof the single sleeve has a helical slit along a predetermined length ofthe sleeve, defining a spiral cut region and a continuous tubularregion. Yet another preferred embodiment has a spiral cut region and acontinuous tubular region, the continuous tubular region comprising adimpled region and a straight tubular region. The dimples may beround-like, spiral, triangular, oval, oblong, circular (like tiretreads) around the circumference or at an angle around thecircumference, or combinations thereof. The dimples may also be of anyother suitable configuration. In another alternative embodiment, thesingle sleeve may comprise a dimpled region extending along part of thesingle sleeve or the entire sleeve.

The present invention also provides a catheter having an expandabledistal portion constructed and arranged for expanding the outer diameterof the catheter from a contracted state to an expanded state. The distalportion of the catheter may further comprise one or two dams (alsoreferred to as enlarged portions, stops, bumpers, longitudinal motionpreventers, or the like) and a balloon. The balloon is folded orotherwise collapsed, and is expandable to an expanded condition. Thecatheter further comprises a balloon protector means comprisingremovable first and second sleeves. The first removable (inner) sleeveis positioned over the balloon and between the dams (where two dams arepresent), the inner sleeve being made of a lubricious material andfurther comprising a first end, a second end and a slit extendingtherethrough. The slit may extend from end to end. Alternatively, theslit may extend along a predetermined length of the sleeve, the rest ofthe length of the sleeve comprising a continuous tube. The continuoustube may further comprise a dimpled region and a straight tubularregion. The slit provides a variable inner diameter to ease sliding thesleeve over the balloon. The second removable (outer) sleeve ispositioned over the first sleeve and dams, the outer sleeve having aconstrictive relationship with the inner sleeve. The outer sleevethereby provides an additional compressive force to reduce the profileof the collapsed balloon. For example, the outer sleeve may have aninner diameter less than the outer diameter of the inner sleeve, wherebywhen compressed by the outer sleeve, the inner sleeve will have an innerdiameter approximately equal to or less than the outer profile of thecollapsed balloon over the dam(s). The inner and outer sleeves areremoved prior to use of the catheter.

Alternatively, the balloon protector may comprise a single compressivesleeve. This single compressive sleeve may be of any configurationdescribed herein. A preferred embodiment of the single sleeve has a slitalong the length thereof. Another preferred embodiment of the singlesleeve has a helical slit along a predetermined length of the sleeve,defining a spiral cut region and a continuous tubular region. Yetanother preferred embodiment has a spiral cut region and a continuoustubular region, the continuous tubular region comprising a dimpledregion and a straight tubular region. The dimples may be round-like,spiral, triangular, oblong, longitudinal, circular (like tire treads)around the circumference or at an angle to the circumference, orcombinations thereof The dimples may also be of any other suitableconfiguration. In another alternative embodiment, the single sleeve maycomprise a dimpled region extending along part of the single sleeve orthe entire sleeve.

The present invention also provides a stent delivery system including acatheter having an expandable distal portion constructed and arrangedfor expanding the outer diameter of the catheter from a contracted stateto an expanded state. The distal portion of the catheter may furthercomprise one or two dams (also referred to as enlarged portions, stops,bumpers, longitudinal motion preventers, or the like) and a balloon. Astent is positioned around the distal portion of the catheter. Wherethere is a single dam, the stent may be positioned either proximally ordistally of the dam. In an embodiment having a single proximal dam, thestent is positioned distally of the proximal dam. In an embodimenthaving a single distal dam, the stent is positioned proximally of thedistal dam. Where two spaced dams are present, the stent is positionedbetween the dams, i.e. distally of the proximal dam and proximally ofthe distal dam. The stent has a contracted condition, being sized in thecontracted condition to closely surround the balloon (the balloon insuch instance being folded or otherwise collapsed), and being expandableto an expanded condition. The stent delivery system further comprises astent protector means comprising removable first and second sleeves. Thefirst removable (inner) sleeve is positioned around the stent andbetween the dams, the inner sleeve being made of a lubricious materialand further comprising a first end, a second end and an expansion slitextending therethrough. The slit may extend from end to end.Alternatively, the slit may extend along a predetermined length of thesleeve, the rest of the length of the sleeve comprising a continuoustube. The continuous tube may further comprise a dimpled region and astraight tubular region. The slit provides a variable inner diameter toease sliding the sleeve over the balloon and stent. The second removable(outer) sleeve is positioned over the stent, first sleeve and dams, theouter sleeve having a constrictive relationship with the inner sleeve.The outer sleeve thereby provides an additional compressive force toreduce the profile of the stent and collapsed balloon. For example, theouter sleeve may have an inner diameter less than the outer diameter ofthe inner sleeve, whereby when compressed by the outer sleeve, the innersleeve will have an inner diameter approximately equal to or less thanthe outer profile of the collapsed balloon over the dam(s). The stentprotector means provides reduction of the profile of the compressedstent over the collapsed balloon.

Alternatively, the stent protector means may comprise a singlecompressive sleeve. This single compressive sleeve may be of anyconfiguration described herein. A preferred embodiment of the singlesleeve has a slit along the length thereof. Another preferred embodimentof the single sleeve has a helical slit along a predetermined length ofthe sleeve, defining a spiral cut region and a continuous tubularregion. Yet another preferred embodiment has a spiral cut region and acontinuous tubular region, the continuous tubular region comprising adimpled region and a straight tubular region. The dimples may beround-like, spiral, triangular, oblong, longitudinal, circular (liketire treads) around the circumference or at an angle to thecircumference, or combinations thereof. The dimples may also be of anyother suitable configuration. In another alternative embodiment, thesingle sleeve may comprise a dimpled region extending along part of thesingle sleeve or the entire sleeve. The sleeve(s) are removed prior touse of the stent delivery system.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a side view of a balloon catheter with a balloon protectoraccording to the present invention having inner and outer sleeves,wherein the distal portion of the catheter thereof is in longitudinalsection view which is enlarged relative to the proximal portion of saidcatheter;

FIG. 2 is an even more enlarged view in longitudinal cross-section ofthe distal portion of the catheter of FIG. 1 (indicated by dashed circle2);

FIG. 3 is a perspective view of a balloon protector sleeve according tothe present invention;

FIG. 3a is a side view thereof;

FIG. 4a is a perspective view of an alternative balloon protector sleeveaccording to the present invention and FIG. 4b is a side partial sectionview of an alternative balloon protector sleeve according to the presentinvention;

FIG. 5 is an even more enlarged cross-section view taken along line 5—5of FIG. 1;

FIGS. 6a-c are side views of alternative balloon protector sleevesaccording to the present invention;

FIG. 7 is a side section view of an alternative balloon protector sleeveaccording to the present invention;

FIG. 8 is a side view of a further alternative balloon protector sleeveaccording to the present invention;

FIGS. 9a-i are side views of further alternative balloon protectorsleeves according to the present invention;

FIGS. 10a-d are perspective views of further alternative balloonprotector sleeves according to the present invention;

FIG. 11 is a side view of a balloon catheter with a balloon protectoraccording to the present invention, wherein the distal portion of thecatheter thereof is in longitudinal section view which is enlargedrelative to the proximal portion of said catheter;

FIG. 12 is a side sectional view taken along line 12—12 of FIG. 11;

FIG. 13 is a side view of an alternative balloon catheter with balloonprotector according to the present invention, wherein the distal portionof the catheter thereof is in longitudinal section view which isenlarged relative to the proximal portion of said catheter;

FIG. 14 is an even more enlarged view in longitudinal cross-section ofthe distal portion of the catheter of FIG. 13 (indicated by dashedcircle 14);

FIG. 15 is a side view of an alternative balloon catheter with balloonprotector according to the present invention, wherein the distal portionof the catheter thereof is in longitudinal section view which isenlarged relative to the proximal portion of said catheter;

FIG. 16 is an even more enlarged view in longitudinal cross-section ofthe distal portion of the catheter of FIG. 15 (indicated by dashedcircle 16);

FIG. 17 is a side view of an alternative balloon catheter with balloonprotector according to the present invention, wherein the distal portionof the catheter thereof is in longitudinal section view which isenlarged relative to the proximal portion of said catheter;

FIG. 18 is an even more enlarged view in longitudinal cross-section ofis the distal portion of the catheter of FIG. 17 (indicated by dashedcircle 17),

FIG. 19 is a side view of a stent delivery system according to thepresent invention with stent protector according to the presentinvention, wherein the distal portion of the catheter thereof is inlongitudinal section view which is enlarged relative to the proximalportion of said catheter;

FIG. 20 is an even more enlarged view in longitudinal cross-section ofthe distal portion of the stent delivery system of FIG. 19 (indicated bydashed circle 20);

FIG. 21 is a side view of an alternative stent delivery system withstent protector according to the present invention, wherein the distalportion of the catheter thereof is in longitudinal section view which isenlarged relative to the proximal portion of said catheter;

FIG. 22 is an even more enlarged view in longitudinal cross-section ofthe distal portion of the stent delivery system of FIG. 21 (indicated bydashed circle 22),

FIG. 23 is a side view of an alternative balloon catheter with balloonprotector according to the present invention, wherein the distal portionof the catheter thereof is in longitudinal section view which isenlarged relative to the proximal portion of said catheter;

FIG. 24 is an even more enlarged view in longitudinal cross-section ofthe distal portion of the stent delivery system of FIG. 23 (indicated bydashed circle 24);

FIG. 25 is an enlarged cross-section view taken along line 25—25 ofFIGS. 19, 21 and 23;

FIG. 26 is a perspective view of a stent protector sleeve according tothe present invention;

FIG. 27a is a perspective view of an alternative stent protector sleeveaccording to the present invention, and FIG. 27 is a side partialsection view of an alternative stent protector sleeve according to thepresent invention;

FIGS. 28a-c are side views of alternative balloon protector sleevesaccording to the present invention;

FIG. 29 is a side section view of an alternative stent protector sleeveaccording to the present invention;

FIG. 30 is a side view of a further alternative stent protector sleeveaccording to the present invention;

FIGS. 31a-i are side views of further alternative stent protectorsleeves according to the present invention;

FIGS. 32a-d are perspective views of further alternative stent protectorsleeves according to the present invention;

FIG. 33 is a side view of a stent delivery system with a stent protectoraccording to the present invention, wherein the distal portion of thecatheter thereof is in longitudinal section view which is enlargedrelative to the proximal portion of said catheter;

FIG. 34 is a cross sectional view of the stent delivery system of claim33 taken along line 34—34; and

FIG. 35 is a side view of a stent delivery system with a stent protectoraccording to the present invention, wherein the distal portion of thecatheter thereof is in longitudinal section view which is enlargedrelative to the proximal portion of said catheter;

FIG. 36 is a cross sectional view of the stent delivery system of claim35 taken along line 36—36;

FIGS. 37-42 are cross sectional views of a stent delivery system as inFIGS. 33 and 35, showing alternative configurations of a stent protectormeans thereof; and

FIGS. 43-45 are schematic representations of means for expanding theexpandable member of the balloon catheters and stent delivery systems ofthe present invention.

FIGS. 46-48 are side partial section views of alternative embodiments ofa single sleeve balloon protector having a continuous tubular region anda region having a helical slit therein defining a spiral cut region;

FIG. 49 is a longitudinal section view of a balloon catheter with aballoon protector according to the present invention;

FIG. 50 is a perspective view of a single sleeve balloon protectoraccording to the present invention, the balloon protector having ahelical slit therein defining a spiral cut region, and a continuoustubular region further comprising a dimpled region and a straighttubular region;

FIG. 51 is a side cross sectional view of the balloon protector as inFIG. 50, taken along the longitudinal axis thereof;

FIG. 52 is a perspective view of a single sleeve balloon protectoraccording to the present invention, the balloon protector having ahelical slit therein defining a spiral cut region, and a continuoustubular region further comprising a dimpled region and a straighttubular region;

FIG. 53 is a side cross sectional view of the balloon protector as inFIG. 52, taken along the longitudinal axis thereof,

FIG. 54 is a perspective view of a single sleeve balloon protectoraccording to the present invention, the balloon protector having adimpled region;

FIG. 55 is a side cross sectional view of the balloon protector as inFIG. 54, taken along the longitudinal axis thereof, and

FIG. 56 is a perspective view of a single sleeve balloon protectoraccording to the present invention, the balloon protector having adimpled region along the entire length thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1-2, a medical device comprising a balloon catheterwith a balloon protector according to the present invention is generallyindicated at 10.

As shown at FIG. 1, catheter 12 has a shaft 13, a proximal portion 14and a distal portion, indicated generally at 16, in longitudinal sectionview which is enlarged relative to the view of the proximal portion ofsaid catheter. Distal portion 16 is fixed to catheter 12 by standardmeans known in the art. For instance, distal portion 16 may be bonded atits ends by adhesive to the catheter in an integral manner, or may bemade one-piece with the catheter as is known in the art. Distal endportion 16 comprises balloon 22, which is constructed and arranged forexpansion from a contracted state to an expanded state. FIG. 2 showsdistal end portion 16 in an even more enlarged longitudinalcross-sectional view.

Balloon 22 may be of any length. For instance, balloon 22 may be about15 mm long. This length, however, is for illustrative purposes only andis not meant to be limiting. Balloon 22 is shown in its contracted statein FIGS. 1-2. Balloon 22 may be folded or otherwise collapsed. Balloon22 or any balloon set forth herein, may be made of a material whichresiliently deforms under radial pressure. Examples of as suitablematerials are generally known in the art and include non-compliant,semi-compliant and compliant materials such as polyethylene (PE), nylon,polyether block amides (PEBAX), polyethylene terephthalate (PET),silicone, POC and the like. In addition, balloon 22 or any balloon setforth herein could be made of amnitel resin, such as Arnitel EM 740 soldby DSM Engineering Plastics, as set forth in U.S. Pat. No. 5,556,383,incorporated herein by reference.

In use, balloon 22 has a larger diameter which is obtained when theballoon 22 is expanded in the known manner. Catheter balloon 22 may beinflated by fluid (gas or liquid) from an inflation port extending froman inflation lumen contained in the catheter shaft 13 and opening intothe balloon 22, or by other means, such as from fluid communication froma passageway or passageways formed between the outside of the cathetershaft and the membrane forming the balloon (schematically shown at FIGS.43-45), depending on the design of the catheter. The passageway(s) couldbe either lead from the catheter shaft directly to the interior of theballoon (as shown at A in FIG. 43) or could lead to the exterior of theballoon (as shown at B of FIG. 44). The catheter may be associated witha source of fluid (gas or liquid) external to the catheter(schematically shown at FIG. 43), whereby the fluid is delivered to theballoon or expandable member by an inflation lumen located in thecatheter shaft 13 and associated with the balloon 22. The details andmechanics of balloon inflation and specific overall catheterconstruction will vary according to the design of the catheter, and areknown in the art per se. All of these variations are acceptable for usewith the balloon catheters and stent delivery systems of the presentinvention.

Balloon catheter 10 further comprises balloon protector means, indicatedgenerally at 26, comprising two removable sleeves. Two sleeves asdescribed herein enhance compression of the balloon and provide a betterprofile. First removable (inner) protector sleeve 28 and secondremovable (outer) protector sleeve 40 may be made of any suitablelow-friction material. Inner and outer sleeves 28,40 may be made of alow friction material which also will not stick to catheter 12 orballoon 22. A non-limiting example of a suitable material in ispolytetrafluoroethylene. Inner sleeve 28 may be made of a lubriciousplastic material or a material which is lubriciously coated.

In an alternative embodiment, outer balloon protector may be made of ashape memory metal or a shape memory polymer. The memory metal andmemory polymer materials can be cast or molded and stretched to a largersize inner diameter. An outer balloon protector made of these materialsprovides the advantage of ease of insertion of the balloon therein sincethe balloon protector starts out with a larger diameter. Upon thermal ormechanical activation (such as by heating or twisting, for example) ofthe balloon protector of memory material, the balloon protector shrinksand tightens down, providing a reduced profile. Use of the inventivememory polymer balloon protector may require additional compression ofthe balloon before the set. A balloon protector made of a shape memorymetal or shape memory polymer may be used with or without an innersleeve.

As shown at FIGS. 1-2, first removable (inner) sleeve 28 is positionedaround balloon 22. Inner sleeve 28 has a length less than or equal tothe length of balloon 22 in its compressed state. Inner sleeve 28comprises a straight tube with a first end 32, a second end 34 and aslit 36 therethrough (shown best at FIGS. 3, 3 a).

Slit 36 extends all the way along inner sleeve 28, from first end 32 tosecond end 34. Slit 36 is shown in FIGS. 3, 3 a as a longitudinal slit37 extending the length of inner sleeve 28. An alternative embodiment ofinner sleeve 28, as shown in FIGS. 4a and 4 b, has a spiral slit 39.Optionally, inner sleeve 28 may have a tail 38 at its second end 34, toassist in its removal. Any outer sleeve, or a singular sleeve accordingto the present invention may be provided with the same configuration asshown at FIGS. 3-4 and 6-10.

Inner protector sleeve 28 is applied to catheter 12 over balloon 22 bymoving inner sleeve 28 in a proximal direction from the distal end 16 ofcatheter 12, or alternatively by moving inner sleeve 28 in a distaldirection from proximal end 14 of catheter 12. Inner sleeve 28 is gentlyurged over balloon 22 as sleeve is moved in a proximal directionrelative to catheter 12. Slit 36 provides inner sleeve 28 with avariable inner diameter, which reduces the force required to apply innersleeve 28 over balloon 22 by reducing friction between balloon 22 andthe interior wall of inner sleeve 28. This ensures that balloon 22 andinner sleeve 28 will not be damaged during application or removal.

Referring to FIG. 5, an enlarged cross-sectional view, second removable(outer) sleeve 40 is positioned over balloon 22 and inner sleeve 28.Balloon 22 is shown in its contracted state in FIG. 5.

Outer sleeve 40 as shown in FIGS. 1-2 is a straight tube. Referring toFIGS. 6a-c, outer sleeve 40 may be a traditional balloon protector asshown at FIG. 6a having a main tubular body portion 42 with a proximalend 44 and a distal end 46 and having a flange 48 at its proximal end44, a sleeve as shown at FIG. 6b with a flange 49 at its distal end 46,or as shown at FIG. 6c with flanges 48,49 at both proximal and distalends 44,46. Sleeve 40 may also be a straight tube 50 with a tapered“lead-in” 52 as shown at FIG. 7, or the like. Other configurations willbe readily apparent to those familiar with this art. The sleeves shownat FIGS. 6a-c can also be used as an outer sleeve with any suitableinner sleeve. The sleeve shown at FIG. 7 may also be used as a singlesleeve balloon protector.

Referring to FIG. 8, an inner sleeve, outer sleeve or singular sleeveballoon protector of the present invention may also be provided in theform of a polymeric tube 60 with flared proximal end 62, flared distalend 64 and a longitudinal slit 37. This inventive balloon protector isunique in that the balloon protector can be removed from the catheterafter the catheter has been prepped and loaded onto a guide wire. Thisallows the balloon protector to be peeled off the shaft, like peeling abanana. Such a construction allows a doctor to prep and introduce theguide wire into the catheter without touching the balloon.

A balloon protector according to the present invention may be a spiralsleeve 66 made of a polymeric material or a metal ribbon. It can also beformed by spiral cutting a tube to be the balloon protector, in aconfiguration as shown in FIGS. 9a-i and as shown at FIGS. 4a-b. Thisballoon protector conforms to diameter changes throughout the length ofthe collapsed balloon, and in a preferred embodiment has a pre-mountedinner diameter which is less than the outer diameter of the collapsedballoon to provide radial compression when applied on the balloon. Theradial strength of the spiral sleeve is related to the material of whichthe sleeve is made, the pitch of the spiral, the wall thickness of thesleeve and the inner diameter of the sleeve. A preferred material forthis balloon protector is LDPE. The spiral sleeve provides a device witha compressive force that has flexibility to conform to diameter changesof a collapsed balloon (a balloon which when expanded has a nonuniformdiameter). The spiral sleeve 66 may be used alone as a single balloonprotector, or as an inner sleeve with any suitable outer sleeve, forexample, a sleeve with a longitudinal slit as shown at FIGS. 3 and 8.The spiral sleeve 66 may also be used as an outer sleeve with anysuitable inner sleeve, for example, a sleeve with a longitudinal slit asshown at FIGS. 3 and 8.

FIGS. 9a-i show alternative embodiments of a spiral sleeve according tothe present invention. FIGS. 9a and 9 b show a spiral sleeve with aflare at one end, FIG. 9a showing a spiral sleeve with a proximal flare48, and FIG. 9b showing a distal flare 49. FIG. 9c shows a spiral sleeve66 with proximal and distal flares 48,49. Prior to use (in a premountedstate) the spiral sleeves shown in FIGS. 9a-c have a substantiallyuniform outer diameter, inner diameter and wall thickness. FIG. 9d showsa spiral sleeve with proximal and distal flares 48,49. FIG. 9e shows aspiral sleeve with a distal flare. FIG. 9f shows a spiral sleeve with aproximal flare. Prior to use (in a premounted state) the spiral sleevesshown in FIGS. 9d-f have a substantially uniform outer diameter, anonuniform, tapered inner diameter and a nonuniform wall thickness. FIG.9g shows a spiral sleeve with proximal and distal flares 48,49. FIG. 9 hshows a spiral sleeve with a proximal flare 48. FIG. 9i shows a spiralsleeve with a distal flare 49. Prior to use (in a premounted state)FIGS. 9g, h and i have a non-uniform tapered inner and outer diameter,and a substantially uniform wall thickness.

A balloon may have various geometries over its length due to non-uniformareas. The spiral sleeve will conform around all portions and compressthem. Following construction of a catheter, the balloon is formed andmay be folded in multiple ways. For example, the balloon may be foldedin a tri-fold manner.

Referring now to FIGS. 10a-d, a further embodiment of a balloonprotector means according to the present invention may be provided inthe form of a coiled flat wire 70, spring wound without a gap betweenthe coils, as shown at FIGS. 10a and 10 c. Prior to thermal (such as byheating, for example), the coiled flat wire 70 may have a configurationas shown in FIGS. 10b and 10 d. Upon thermal activation, the coiled flatwire 70 shrinks and tightens down, providing a reduced profile as shownin FIGS. 10a and 10 c. Prior to mechanical activation, the coiled flatwire 70 may have a configuration as shown in FIGS. 10a and 10 c. Uponmechanical activation (such as by twisting, for example), the coiledflat wire 70 is expanded to a configuration as shown in FIGS. 10b and 10d, allowing it to be applied on the catheter. Releasing the coiled flatwire 70 allows it to shrink and tighten down, providing a reducedprofile as shown in FIGS. 10a and 10 c. The coiled flat wire 70 may alsobe provided in a configuration as shown in FIGS. 4a-b. The embodimentshown at FIGS. 10a-d has an optional mechanical activation means 71.Mechanical activation means may be removable following mechanicalactivation or alternatively may be constructed and arranged forretention with coiled wire sleeve 70 and removal prior to use ofcatheter 12. The mechanical activation means may be of any suitableconfiguration, and is not intended to be limited hereby.

This outer balloon protector is a “one size fits all” which willaccommodate all balloons, with or without stents in a deliveryconfiguration. The advantages provided by this configuration is that itprovides a “better squeeze” or higher externally applied compressiveforce than previous press-fit balloon protectors in the art. Thisconfiguration provides a compressive force that is variable along thelength of the device, thereby providing a uniform compression amountalong the entire length of a device which may or may not have a variablediameter. This balloon protector is easier to apply to a balloon thanprevious balloon protectors known in the art. Since the collapse columnstrength and friction forces are taken out of the assembly process, theproduction yield associated with catheters employing this balloonprotector is improved.

Prior to placement of sleeves 28 and 40 on the catheter, outer sleeve 40has an inner diameter less than the outer diameter of the inner sleeve28. In a preferred embodiment, the inner diameter of outer protectorsleeve 40 slightly smaller (about 0.001 inch smaller, for example) thanthe outer diameter of inner protector sleeve 28. This causes slit 36 tobe closed when outer protector sleeve 40 is applied over inner protectorsleeve 28, in addition to overall compression of inner protective sleeve28. Inner sleeve 28 locates and holds balloon 22 while relatively tightouter sleeve 40 is pulled on. The lubricity of inner sleeve 28 reducesfriction and enables outer sleeve 40 to be easily applied and removedfrom inner sleeve 28. Inner sleeve 28 provides the additional benefit ofprotecting the balloon 22 from damage.

As slit 36 is closed and forced together by outer protective sleeve 40,balloon 22 becomes more tightly wrapped and held. When outer sleeve 40is in place, inner sleeve 28 is compressed by outer sleeve 40, andcompressed inner sleeve 28 has an inner diameter approximately equal tothe outer diameter of the compressed balloon. Outer sleeve 40 closesslit 36, and holds inner sleeve 28, and balloon 22 in place duringsterilization and heat set profile forming (such as is disclosed in U.S.Pat. No. 5,342,307, incorporated herein by reference).

After both sleeves 28,40 are in place at distal end 16 of catheter 12, aheated sterilization cycle may be performed. Balloon 22 will thereby byheat set into a further compressed form. The heat setting of balloon 22provides a “memory” to balloon 22 so that when inner and outer sleeves28,40 are removed prior to use, balloon 22 will remain in its compressedform. Even after inflation and deflation balloon 22 will tend to returnto substantially the same shape as it had during the heat sterilizationprocess. Therefore, small profiles can be achieved even after ballooninflation.

Inner and outer sleeves 28,40 are removed from catheter 12 prior to usethereof. Outer sleeve 40 is removed by pulling it off catheter 12. Innersleeve 24 is removed in like manner, or pulled off using optional tail38.

During delivery, the balloon catheter is advanced through and positionedin a patient's vasculature so that balloon is adjacent to the portion ofthe vessel where treatment is to take place. Balloon 22 is inflated andexpanded to an enlarged diameter. Following use of balloon 22, balloon22 is deflated so that catheter 12 may be removed.

Referring now to FIGS. 11 and 12, wherein like features are designatedby the same reference numerals, an alternative embodiment of a ballooncatheter having a balloon protector according to the present inventionis shown, wherein like features are designated by the same referencenumerals as in FIG. 1. Balloon 22 is a folded balloon and the balloonprotector 40 as shown is a single sleeve. Although any suitable sleeveaccording to the present invention may be used, the sleeve showncorresponds to that shown in FIG. 7.

Referring now to FIGS. 13-14, a balloon catheter with a balloonprotector according to the present invention is generally indicated at10.

As shown at FIG. 14, catheter 12 has a shaft 13, a proximal portion 14and a distal portion, indicated generally at 16, in longitudinal sectionview which is enlarged relative to the view of the proximal portion ofsaid catheter. Distal portion 16 is fixed to catheter 12 by standardmeans known in the art. For instance, distal portion 16 may be bonded atits ends by adhesive to the catheter in an integral manner, or may bemade one-piece with the catheter as is known in the art. Distal endportion 16 comprises balloon 22, which is constructed and arranged forexpansion from a contracted state to an expanded state. FIG. 14 showsdistal end portion 16 in an even more enlarged longitudinalcross-sectional view. As shown in FIGS. 13-14, distal end portion 16further comprises a distal dam (or stop) 20. Darn 20 may be conical orringlike in shape, extending around the circumference of catheter 12.The majority of balloon 22 is located proximally of distal dam 20, aportion of balloon 22 covering and extending distally of distal dam 20.

As shown at FIGS. 15-16, which correspond respectively to FIGS. 13-14and wherein like features are designated by the same reference numerals,catheter 12 may also have a single dam located at its proximal portion.In this embodiment, the majority of balloon 22 is located distally ofproximal dam 18, a portion of the balloon 22 covering and extendingproximally of proximal dam 18.

Referring to FIGS. 17-18, which correspond respectively to FIGS. 13-14,and wherein like features are designated by the same reference numerals,an alternative embodiment of balloon catheter 12 is shown wherein distalportion 16 further comprises proximal dam 18 spaced a predetermineddistance from distal dam 20. Balloon 22 is located over and between dams18,20.

Balloon 22 is shown in its contracted state in FIGS. 13-18. Balloon 22may be folded or otherwise collapsed. Balloon 22 may be of any length.For instance, balloon 22 may be about 15 rmm long in its contractedstate. This length, however, is for illustrative purposes only and isnot meant to be limiting. Balloon 22 may be made of a material whichresiliently deforms under radial pressure. Examples of suitablematerials are generally known in the art and include non-compliant,semi-compliant and compliant materials such as polyethylene (PE), nylon,polyether block amides (PEBAX), polyethylene terephthalate (PET),silicone, POC and the like. In addition, balloon 22 could be made ofamnitel resin, such as Amnitel EM 740 sold by DSM Engineering Plastics,as set forth in U.S. Pat. No. 5,556,383, incorporated herein byreference.

In use, balloon 22 has a larger diameter which is obtained when theballoon 22 is expanded in the known manner. Catheter balloon 22 may beinflated by fluid (gas or liquid) from an inflation port extending froma lumen contained in the catheter shaft 13 and opening into the balloon,or by other means, such as from fluid communication from a passagewayformed between the outside of the catheter shaft and the membraneforming the balloon, depending on the design of the catheter. Thecatheter may be associated with a source of fluid (gas or liquid)external to the catheter, whereby the fluid is delivered to the balloonor expandable member by an inflation lumen located in the catheter shaft13 and associated with the balloon 22. The details and mechanics ofballoon inflation and specific overall catheter construction will varyaccording to the design of the catheter, and are known in the art perse. All of these variations are acceptable for use with this invention.

Balloon catheter 10 further comprises balloon protector means, indicatedgenerally at 26, comprising two removable sleeves. Two sleeves asdescribed herein enhance compression of the balloon and provide a betterprofile. In this embodiment, the two sleeves may provide compression ofthe balloon at or below the dam (or stop) profile. First removable(inner) protector sleeve 28 and second removable (outer) protectorsleeve 40 may be made of any suitable low-friction material. Inner andouter sleeves 28,40 may be made of a low friction material which alsowill not stick to catheter 12 or balloon 22. A non-limiting example ofsuch a material is polytetrafluoroethylene. Inner sleeve 28 may be madeof a lubricious plastic material or a material which is lubriciouslycoated.

In an alternative embodiment, outer balloon protector may be made of ashape memory metal or a shape memory polymer. The memory metal andmemory polymer materials can be cast or molded and stretched to a largersize inner diameter. An outer balloon protector made of these materialsprovides the advantage of ease of insertion of the balloon therein sincethe balloon protector starts out with a larger diameter. Upon thermal ormechanical activation (such as by heating or twisting, for example) ofthe balloon protector of memory material, the balloon protector shrinksand tightens down, providing a reduced profile. Use of the inventivememory polymer balloon protector may require additional compression ofthe balloon before the set. A balloon protector made of a shape memorymetal or shape memory polymer may be used with or without an innersleeve.

As shown at FIGS. 17-18, first removable (inner) sleeve 28 is positionedaround balloon 22. Inner sleeve 28 has a length less than or equal tothat of balloon 22 in its compressed state. Inner sleeve 28 comprises astraight tube with a first end 32, a second end 34 and a slit 36therethrough.

Slit 36 extends all the way along inner sleeve 28, from first end 32 tosecond end 34. Slit 36 is shown in FIGS. 3-3a as a longitudinal slit 37extending the length of inner sleeve 28. An alternative embodiment ofinner sleeve 28, as shown in FIGS. 4a and 4 b, has a spiral slit 39.Optionally, inner sleeve 28 may have a tail 38 at its second end 34, toassist in its removal. Any outer sleeve, or a singular sleeve accordingto the present invention may be provided with the same configuration asshown at FIGS. 3-4 and 6-10.

In the embodiment shown at FIGS. 13-18, inner protector sleeve 28 isapplied to catheter 12 over balloon 22 by moving inner sleeve 28 in aproximal direction from the distal end 16 of catheter 12, oralternatively by moving inner sleeve 28 in a distal direction from theproximal end 14 of catheter 12. Inner sleeve 28 is gently urged overballoon 22 as sleeve is moved in a proximal direction relative tocatheter 12.

Slit 36 provides inner sleeve 28 with a variable inner diameter, whichreduces the force required to apply inner sleeve 28 over balloon 22 byreducing friction between balloon 22 and the interior wall of innersleeve 28. This ensures that balloon 22 or inner sleeve 28 will not bedamaged during application or removal.

Referring to FIG. 5, an enlarged cross-sectional view, second removable(outer) sleeve 40 is positioned over balloon 22 and inner sleeve 28.Balloon 22 is shown in its contracted state in FIG. 5. In the embodimentshown at FIGS. 17-18, outer sleeve extends over dams 18,20.

Outer sleeve 40 as shown in FIGS. 13-18 is a straight tube. Referring toFIGS. 6a-c, outer sleeve 40 may be a traditional balloon protector asshown at FIG. 6a having a main tubular body portion 42 with a proximalend 44 and a distal end 46, and having a flange 48 at its proximal end44, as shown at FIG. 6b having a flange 49 at its distal end 46, or asshown at FIG. 6c having flanges 48,49 at proximal and distal ends 44,46.Outer sleeve may be a straight tube 50 with a tapered “lead-in” 52 asshown at FIG. 7. Other configurations will be readily apparent to thosefamiliar with this art. The sleeves shown at FIGS. 6a-c can also be usedas an outer sleeve with any suitable inner sleeve. The sleeve shown atFIG. 7 may also be used as a single sleeve balloon protector.

Referring to FIG. 8, an inner sleeve, outer sleeve or singular sleeveballoon protector of the present invention may also be provided in theform of a polymeric tube 60 with flared proximal end 62, flared distalend 64 and a longitudinal slit 37. This inventive balloon protector isunique in that the balloon protector can be removed from the catheterafter the catheter has been prepped and loaded onto a guide wire. Thisallows the balloon protector to be peeled off the shaft, like peeling abanana. Such a construction allows a doctor to prep and introduce theguide wire into the catheter without touching the balloon.

A balloon protector according to the present invention may be a spiralsleeve made of a polymeric material or a metal ribbon. It can also beformed by spiral cutting a tube to be the balloon protector, in aconfiguration as shown in FIGS. 9a-c or in FIGS. 4a-b. This balloonprotector conforms to diameter changes throughout the length of thecollapsed balloon, and in a preferred embodiment has a pre-mounted innerdiameter which is less than the outer diameter of the collapsed balloonto provide radial compression when applied on the balloon. The radialstrength of the spiral sleeve is related to the material of which thesleeve is made, the pitch of the spiral, the wall thickness of thesleeve and the inner diameter of the sleeve. A preferred material forthis balloon protector is LDPE. The spiral sleeve provides a device witha compressive force that has flexibility to conform to diameter changesof a collapsed balloon (a balloon which when expanded has a non-uniformdiameter). The spiral sleeve 66 may be used alone as a single balloonprotector, or as an inner sleeve with any suitable outer sleeve, forexample, a sleeve with a longitudinal slit as shown at FIGS. 3 and 8.The spiral sleeve 66 may also be used as an outer sleeve with anysuitable inner sleeve, for example, a sleeve with a longitudinal slit asshown at FIGS. 3 and 8.

A balloon may have various geometries over its length due to non-uniformareas. The spiral sleeve will conform around all portions and compressthem. Following construction of a catheter, the balloon is formed andmay be folded in multiple ways. For example, the balloon may be foldedin a tri-fold manner.

Referring to FIGS. 10a-d, a further embodiment of an outer balloonprotector according to the present invention may be provided in the formof a coiled flat wire 70, spring wound without a gap between the coils,as shown at FIGS. 10a and 10 c. Prior to thermal or mechanicalactivation (such as by heating or twisting, for example, the coiled flatwire 70 may have a configuration as shown in FIGS. 10b and 10 d. Uponthermal or mechanical activation, the coiled flat wire 70 shrinks andtightens down, providing a reduced profile as shown in FIGS. 10a and 10c. The embodiment shown at FIGS. 10a-d has an optional mechanicalactivation means 71. Mechanical activation means may be removablefollowing mechanical activation or alternatively may be constructed andarranged for retention with coiled wire sleeve 70 and removal prior touse of catheter 12. The mechanical activation means may be of anysuitable configuration, and is not intended to be limited hereby.

This outer balloon protector is a “one size fits all” which willaccommodate all balloons, with or without stents in a deliveryconfiguration. The advantage provided by this configuration is that itprovides a “better squeeze” or higher externally applied compressiveforce than previous press-fit balloon protectors in the art. Thisconfiguration provides a compressive force that is variable along thelength of the device, thereby providing a uniform compression amountalong the entire length of a device which may or may not have a variablediameter. This balloon protector is easier to apply to a balloon thanprevious balloon protectors known in the art. Since the collapse columnstrength and friction forces are taken out of the assembly process, theproduction yield associated with catheters employing this balloonprotector is improved.

Prior to mounting inner sleeve 28 and outer sleeve 40 on a catheter,outer sleeve 40 has an inner diameter less than the outer diameter ofthe inner sleeve 28. In a preferred embodiment, the inner diameter ofouter protector sleeve 40 is slightly smaller (for example, about 0.001inch smaller) than the outer diameter of inner protector sleeve 28. Thiscauses slit 36 to be closed when outer protector sleeve 40 is appliedover inner protector sleeve 28, in addition to overall compression ofinner protective sleeve 28. Inner sleeve 28 locates and holds balloon 22while relatively tight outer sleeve 40 is pulled on. The lubricity ofinner sleeve 28 reduces friction and enables outer sleeve 40 to beeasily applied and removed from inner sleeve 28. Inner sleeve 28provides the additional benefit of protecting the balloon 22 fromdamage.

As slit 36 is closed and forced together by outer protective sleeve 40,balloon 22 becomes more tightly wrapped and held. When outer sleeve 40is in place, inner sleeve 28 is compressed by outer sleeve 40, andcompressed inner sleeve 28 has an inner diameter approximately equal tothe combined diameter of the compressed balloon and the dam. Outersleeve 40 closes slit 36, and holds inner sleeve 28, and balloon 22 inplace during sterilization and heat set profile forming (such as isdisclosed in U.S. Pat. No. 5,342,307).

After both sleeves 28,40 are in place at distal end 16 of catheter 12, aheated sterilization cycle may be performed. Balloon 22 will thereby byheat set into a further compressed form. The heat setting of balloon 22provides a “memory” to balloon 22 so that when inner and outer sleeves28,40 are removed prior to use, balloon 22 will remain in its compressedform. Even after inflation and deflation balloon 22 will tend to returnto substantially the same shape as it had during the heat sterilizationprocess. Therefore, small profiles can be achieved even after ballooninflation.

Inner and outer sleeves 28,40 are removed from catheter 12 prior to usethereof. Outer sleeve 40 is removed by pulling it off catheter 12. Innersleeve 24 is removed in like manner, or pulled off using optional tail38.

During delivery, the balloon catheter is advanced through and positionedin a patient's vasculature so that balloon is adjacent to the portion ofthe vessel where treatment is to take place. Balloon 22 is inflated andexpanded to an enlarged diameter. Following use of balloon 22, balloon22 is deflated so that catheter 12 may be removed.

Referring to FIGS. 19-20, a stent delivery system according to thepresent invention is indicated generally at 110. As shown at FIG. 20,stent delivery system 110 includes a catheter 112 having a shaft 113, aproximal portion 114 and a distal portion (indicated generally at 116)in longitudinal section view which is enlarged relative to the view ofthe proximal portion of said catheter. Distal portion 116 is fixed tocatheter 112 by standard means known in the art. For instance, distalportion 116 may be bonded at its ends by adhesive to the catheter in anintegral manner, or may be made one-piece with the catheter as is knownin the art. Distal portion 116 is constructed and arranged for expansionof its outer diameter from a contracted state to an expanded state.

FIG. 20 shows distal end portion in an even more enlarged longitudinalcross-sectional view. As shown in FIG. 20, distal end portion 116further comprises a distal dam (or stop) 120. Dam 120 may be conical orring-like in shape, extending around the circumference of catheter 112.Balloon 122 is located proximally of distal dam 120.

As shown at FIGS. 21-22, which correspond respectively to FIGS. 19-20and wherein like features are designated by the same reference numerals,catheter 112 may also have a single dam located at its proximal portion.In this embodiment, balloon 122 is located distally of proximal dam 118.

Referring to FIGS. 23-24, which correspond respectively to FIGS. 19-20,and wherein like features are designated by the same reference numerals,an alternative embodiment of balloon catheter 112 is shown whereindistal portion 116 comprises two dams, proximal dam 118 being spaced apredetermined distance from distal dam 120. Balloon 122 is located overand between dams 118,120.

Balloon is shown in its contracted state in FIGS. 19-24. Balloon 122 maybe folded or otherwise collapsed. Balloon 122 may be made of a materialwhich resiliently deforms under radial pressure. Examples of suitablematerials are generally known in the art and include noncompliant,semi-compliant and compliant materials such as polyethylene (PE), nylon,polyether block amides (PEBAX), polyethylene terephthalate (PET),silicone, POC and the like. In addition, balloon 122 could be made ofamnitel resin, such as Amnitel EM 740 sold by DSM Engineering Plastics,as set forth in U.S. Pat. No. 5,556,383, incorporated herein byreference.

Referring to FIG. 25, an enlarged cross-sectional view of a crosssection taken along line 25—25 of FIGS. 19, 21 and 23, second removable(outer) sleeve 140 is positioned over balloon 122, stent 124 and innersleeve 128. Balloon 122 is shown in its contracted state in FIG. 25. Asshown in FIGS. 19-20, outer sleeve 140 extends over distal dam 120. Asshown in FIGS. 21-22, outer sleeve 140 extends over proximal dam 118. Inthe embodiment shown at FIGS. 23-24, outer sleeve extends over dams118,120.

Referring to FIGS. 19-24, catheter 112 has a shaft 113, a proximalportion 114 and a distal portion, indicated generally at 116, inlongitudinal section view which is enlarged relative to the view of theproximal portion of said catheter. Distal portion 116 is fixed tocatheter 112 by standard means known in the art. For instance, distalportion 116 may be bonded at its ends by adhesive to the catheter in anintegral manner, or may be made one-piece with the catheter as is knownin the art. Distal end portion 116 is constructed and arranged forexpanding the outer diameter of the catheter from a contracted state toan expanded state.

As shown in FIGS. 19-24, stent 124 is positioned around the distalportion of catheter 112 (around balloon 122). As shown in FIGS. 19-20,stent 124 is located proximally of single distal dam 120. As shown inFIGS. 21-22, stent 124 is shown in a location distal to single proximaldam 118. As shown in FIGS. 23-24, stent 124 is positioned around thedistal portion of catheter 112 (around balloon 122) between proximal dam118 and distal dam 120.

Any self-expanding stent or balloon expandable stent may be used withthis invention. Many are known in the art including plastic and metalstents. Some are more well known such as the stainless steel stent shownin U.S. Pat. No. 4,735,665; the wire stent shown in U.S. Pat. No.4,950,227; another metal stent shown in European Patent Application EPO707 837 A1 and that shown in U.S. Pat. No. 5,445,646. All of thesepatents are incorporated herein by reference. Also, shape memory metalstents may be used.

Stent 124 is typically about 15 mm long, while balloon 122 is roughlythe same length. These dimensions, however, are merely representativefor illustrative purposes only and are not meant to be limiting. In theembodiment shown at FIGS. 23-24 having spaced dams 118,120, the upperlimit of the length of stent 124 is defined by the distance between dams118,120.

Stent 124 has a contracted condition and an expanded condition, beingsized in its contracted condition to closely surround the catheter.Stent 124 is fixed about balloon 122 by any suitable means as known inthe art. For example, stent 124 may be gently crimped onto balloon 122either by hand or with a tool such as a pliers or the like to be mountedfor delivery.

Stent 124 has a larger expanded diameter which is obtained when theballoon 122 is expanded in the known manner. That is, stent 124 will bereleased from catheter 112 upon expansion of balloon 122 to be placed ina vessel. When balloon 122 is then deflated, removal of catheter 112 maybe accomplished while leaving stent 124 in place.

Catheter balloon 122 may be inflated by fluid (gas or liquid) from aninflation port extending from a lumen contained in the catheter shaft113 and opening into the balloon 122, or by other means, such as fromfluid communication from a passageway formed between the outside of thecatheter shaft 113 and the membrane forming the balloon, depending onthe design of the catheter. The catheter may be associated with a sourceof fluid (gas or liquid) external to the catheter, whereby the fluid isdelivered to the balloon or expandable member by an inflation lumenlocated in the catheter shaft 113 and associated with the balloon 122.The details and mechanics of balloon inflation and specific overallcatheter construction will vary according to the design of the catheter,and are known in the art per se. All of these variations are acceptablefor use with this invention.

Stent delivery system 110 further comprises stent protector means,indicated generally at 126, comprising two removable sleeves. Twosleeves as described herein provide a better profile and enablecompression of stent 124 below the dam (or stop) profile. Firstremovable (inner) protector sleeve 128 and second removable (outer)protector sleeve 140 may be made of any suitable low-friction material.Inner and outer sleeves 128,140 may be made of a low friction materialwhich also will not stick to catheter 112, balloon 122 or stent 124. Anexample of a such a material is polytetrafluoroethylene. Inner sleeve128 may be made of a lubricious plastic material or a material which islubriciously coated.

In alternative embodiment, the outer balloon protector according to thepresent invention may be made of a shape memory metal or a shape memorypolymer. Such memory metal and memory polymer materials can be cast ormolded and stretched to a larger size inner diameter. Such a stentprotector provides the advantage of ease insertion of the catheter andstent since the stent protector starts out with a larger diameter. Uponthermal or mechanical activation (such as by heating or twisting, forexample) of the stent protector of memory material, the stent protectorshrinks and tightens down, providing a reduced profile. Use of theinventive memory polymer stent protector will require additionalcompression of the balloon and stent before the set. Such a stentprotector may be used with or without an inner sleeve.

As shown at FIGS. 19-24, first removable (inner) sleeve 128 ispositioned around stent 124. Inner sleeve 128 has a length approximatelyequal to that of stent 124 in its compressed state on catheter 112.Inner sleeve 128 comprises a straight tube with a first end 132, and asecond end 134 and a slit 136 therethrough (as shown at FIG. 26).

Slit 136 extends all the way along inner sleeve 128, from first end 132to second end 134. Slit 136 is shown in FIG. 26 as a longitudinal slit137 extending the length of inner sleeve 128. An alternative embodimentof inner sleeve 128, as shown in FIGS. 27a and 27, has a spiral slit139. Optionally, inner sleeve 128 may have a tail 138 at its second end134, to assist in its removal. Any outer sleeve, or a singular sleeveaccording to the present invention may be provided with the sameconfiguration as shown at FIGS. 26-27, 27 a and 28-32.

In the embodiment shown at FIGS. 19-24, inner protector sleeve 128 maybe applied to catheter 112 over balloon 122 and stent 124 by movinginner sleeve 128 in a proximal direction from the distal end 116 ofcatheter 112. Inner sleeve 128 is then gently urged over stent 124 assleeve is moved in a proximal direction relative to catheter 112.Alternatively, inner protector sleeve 128 may be applied to catheter 112over balloon 122 and stent 124 by moving inner sleeve 128 in a distaldirection from the proximal end 114 of catheter 112, and inner sleeve128 is then gently urged over stent 124 as sleeve is moved in a distaldirection relative to catheter 112.

Slit 136 provides inner sleeve 128 with a variable inner diameter, whichreduces the force required to apply inner sleeve 128 over stent 124 byreducing friction between stent 124 and the interior wall of innersleeve 128, and allows inner sleeve 128 to fit over the dam(s). Thisensures that balloon 122 or inner sleeve 128 will not be damaged bystent 124 during application or removal.

Outer sleeve 140 as shown in FIGS. 19-24 is a straight tube. Referringto FIGS. 28a-c, outer sleeve 140 may be a traditional balloon protectoras shown at FIG. 28a having a main tubular body portion 142 with aproximal end 144 and a distal end 146 and having a flange 148 at itsproximal end 144, as shown at FIG. 28b with a flange 149 at its distalend 146, or as shown at FIG. 28c with flanges 148,149 at both ends144,146. Referring to FIG. 29, outer sleeve 140 may be a straight tube150 with a tapered “lead-in” 152. Other configurations will be readilyapparent to those familiar with this art. The sleeves shown at FIGS.28a-c can also be used as an outer sleeve with any suitable innersleeve. The sleeve shown at FIG. 29 may be used as a single sleeveballoon protector.

Referring to FIG. 30, an inner sleeve, outer sleeve or singular sleevestent protector of the present invention may also be provided in theform of a polymeric tube 160 having flared proximal end 162, flareddistal end 164 and longitudinal slit 137. This inventive stent protectoris unique in that the stent protector can be removed from the catheterafter the catheter has been prepped and loaded onto a guide wire. Thisallows the stent protector to be peeled off the shaft, like peeling abanana. Such a construction allows a doctor to prep and introduce theguide wire into the catheter without touching the preloaded stent.

Referring now to FIGS. 31a-i, a further alternative embodiment of astent protector according to the present invention is a spiral sleeve166 made of a polymeric material or a metal ribbon. The spiral sleevecan also be formed by spiral cutting a tube to be the stent protector,in a configuration as shown in FIGS. 31a-c and 27 a and 27. This stentprotector conforms to diameter changes throughout the length of thestent and compressed balloon, and in a preferred embodiment has apre-mounted inner diameter which is less than the outer diameter of thecollapsed balloon to provide radial compression when applied on theballoon. The radial strength of the spiral sleeve is related to thematerial of which the sleeve is made, the pitch of the spiral, the wallthickness of the sleeve and the inner diameter of the sleeve. Apreferred material for this balloon protector is LDPE. The spiral sleeveprovides a device with a compressive force that has flexibility toconform to diameter changes of a collapsed balloon (a balloon which whenexpanded may have a nonuniform diameter) on which a stent is loaded. Thespiral sleeve 166 may be used alone as a single stent protector, or asan inner sleeve with any suitable outer sleeve, for example, a sleevewith a longitudinal slit as shown at FIG. 26. The spiral sleeve 166 mayalso be used as an outer sleeve with any suitable inner sleeve, forexample, a sleeve with a longitudinal slit as shown at FIG. 26.

FIGS. 31a-i show alternative embodiments of a spiral sleeve 166according to the present invention. FIG. 31a and 31 b show a spiralsleeve with a flare at one end, FIG. 31a showing a spiral sleeve with aproximal flare 148, and FIG. 31b showing a distal flare 149. FIG. 31cshows a spiral sleeve 166 with proximal and distal flares 148,149. Priorto use (in a premounted state) the spiral sleeves shown in FIGS. 31a-chave a substantially uniform outer diameter, inner diameter and wallthickness. FIG. 31d shows a spiral sleeve with proximal and distalflares 148,149. FIG. 31e shows a spiral sleeve with a distal flare 149.FIG. 31f shows a spiral sleeve with a proximal flare 148. Prior to use(in a premounted state) the spiral sleeves shown in FIGS. 31d-f have asubstantially uniform outer diameter,a non-uniform, tapered innerdiameter and a nonuniform wall thickness. FIG. 31g shows a spiral sleevewith proximal and distal flares 148,149. FIG. 31h shows a spiral sleevewith a proximal flare 148. FIG. 31i shows a spiral sleeve with a distalflare 149. Prior to use (in a premounted state) FIGS. 31g, h and i havea non-uniform tapered inner and outer diameter, and a substantiallyuniform wall thickness.

This embodiment may be used not only with PTCA balloon catheters, butalso with stent delivery systems comprising catheters on which a stentis loaded. The balloon may be folded in multiple ways. For example, theballoon may be folded in a tri-fold manner. A balloon may have variousgeometries over its length due to non-uniform areas. The stent may becrimped to the balloon. The spiral sleeve will conform around allportions and compress them.

Referring now to FIGS. 32a-d, a further embodiment of an outer stentprotector according to the present invention may be provided in the formof a coiled flat wire 170, spring wound without a gap between the coils,as shown at FIGS. 32a and 32 c. Prior to thermal (such as by heating,for example), the coiled flat wire 170 may have a configuration as shownin FIGS. 32b and 32 d. Upon thermal activation, the coiled flat wire 170shrinks and tightens down, providing a reduced profile as shown in FIGS.32a and 32 c. Prior to mechanical activation, the coiled flat wire 170may have a configuration as shown in FIGS. 32a and 32 c. Upon mechanicalactivation (such as by twisting, for example), the coiled flat wire 170is expanded to a configuration as shown in FIGS. 32b and 32 d, allowingit to be applied on the catheter. Releasing the coiled flat wire 170allows it to shrink and tighten down, providing a reduced profile asshown in FIGS. 32a and 32 c. The coiled flat wire 170 may be provided ina configuration as shown at FIGS. 27, 27 a. The embodiment shown atFIGS. 32a-d has an optional mechanical activation means 171. Mechanicalactivation means may be removable following mechanical activation oralternatively may be constructed and arranged for retention with coiledwire sleeve 170 and removal prior to use of catheter 112. The mechanicalactivation means may be of any suitable configuration, and is notintended to be limited hereby.

This outer stent protector is a “one size fits all” which willaccommodate all balloons, with or without stents in a deliveryconfiguration. The advantages provided by this configuration is that itprovides a “better squeeze” or higher externally applied compressiveforce than prior art stent protectors. This configuration provides acompressive force that is variable along the length of the device,thereby providing a uniform compression amount along the entire lengthof a device which may or may not have a variable diameter. This stentprotector is easier to apply over a stent than previous stent protectorsknown in the art. Since the collapse column strength and friction forcesare taken out of the assembly process, the production yield associatedwith stent delivery devices employing this stent protector is improved.

Prior to placement of inner sleeve and outer sleeve 140 on a catheter,outer sleeve 140 has an inner diameter less than the outer diameter ofthe inner sleeve 128. In a preferred embodiment, the inner diameter ofouter protector sleeve 140 is slightly smaller (for example, about 0.001inch smaller) than the outer diameter of inner protector sleeve 128.This causes slit 136 to be closed when outer protector sleeve 140 isapplied over inner protector sleeve 128, in addition to overallcompression of inner protective sleeve 128. Inner sleeve 128 locates andholds stent 124 while relatively tight outer sleeve 140 is pulled on.The lubricity of inner sleeve 128 reduces friction and enables outersleeve 140 to be easily applied and removed from inner sleeve 128. Innersleeve 128 provides the additional benefit of protecting the stent 124from damage.

As slit 136 is closed and forced together by outer protective sleeve140, stent 124 becomes more tightly wrapped and held. When outer sleeve140 is in place, inner sleeve 128 is compressed by outer sleeve 140, andcompressed inner sleeve 128 has an inner diameter approximately equal tothe sum of the diameter of the compressed balloon and the dam(s). Thestent delivery system of the present invention thereby enablescompression of the stent below the dam profile. Outer sleeve 140 closesslit 136, and holds inner sleeve 128, stent 124 and balloon 122 in placeduring sterilization and/or heat set profile forming (such as isdisclosed in U.S. Pat. No. 5,342,307).

After both sleeves 128,140 are in place at distal end 116 of catheter112, a heated sterilization cycle may be performed. Balloon 122 willthereby be heat set into a further compressed form. The heat setting ofballoon 122 provides a “memory” to balloon 122 so that when inner andouter sleeves 128,140 are removed prior to use, balloon 122 will remainin its compressed form. Even after inflation and deflation balloon 122will tend to return to substantially the same shape as it had during theheat sterilization process. Therefore, small profiles can be achievedeven after balloon inflation.

Inner and outer sleeves 128,140 are removed from stent delivery system110 prior to use of the stent delivery system and deployment of stent124 by expansion of the balloon. Outer sleeve 140 is removed by pullingit off catheter 112. Inner sleeve 124 is removed in like manner, orpulled off using optional tail 138.

During delivery, the balloon catheter is advanced through and positionedin a patient's vasculature so that stent 124 is adjacent to the portionof the vessel where treatment is to take place. Balloon 122 is inflatedto expand stent 124 to an enlarged diameter. When stent 124 has reachedthe desired diameter, balloon 122 is deflated so is that catheter 112may be removed leaving stent 124 in place.

Referring now to FIGS. 33 and 35, alternative embodiments of a stentdelivery system according to the present invention are shown generallyat 210. Catheter 212 has a shaft 213, a proximal portion 214 and adistal portion, indicated generally at 216, shown in longitudinalsection view which is enlarged relative to the view of the proximalportion of said catheter. Distal portion 216 is fixed to catheter 212 bystandard means known in the art. For instance, distal portion 216 may bebonded at its ends by adhesive to the catheter in an integral manner, ormay be made one-piece with the catheter as is known in the art. Distalportion 216 is constructed and arranged for expanding the outer diameterof the catheter from a contracted state to an expanded state. Distalportion 216 comprises a balloon 222, which has a proximal end 225, and adistal end 226. In the embodiments shown, proximal end 225 of balloon222 is inwardly tapered and distal end 226 has an enlarged portion 227which extends over distal dam 220. In FIGS. 34 and 36, cross sectionsrespectively taken along line 34—34 of FIG. 33, and line 35—35 of FIG.35, balloon 222 is shown to be a folded balloon in its compressed state.

As shown in FIGS. 33-34, stent 224 is positioned around the distalportion of catheter 212 (around balloon 222) between proximal end 225and distal enlarged portion 227 thereof. This embodiment may be usedwith any stent protector means described herein. Inner sleeve 228 isshown, having approximately the same length as stent 224. Outer sleeve240 is shown having a length greater than or equal to that of balloon224.

As shown in FIGS. 35-36, stent 224 is positioned around balloon 222between proximal end 225 and distal enlarged portion thereof. Thisembodiment may be used with any single sleeve stent protector accordingto the present invention. In a most preferred embodiment of the presentinvention as shown in FIGS. 35 and 36, the stent protector correspondsto that shown in FIGS. 27-27a or 31 a-i.

Referring now to FIGS. 37-42, cross sectional views showing alternativeconfigurations of a stent protector means indicated generally in FIGS.33-40 at 226. In the embodiment shown in FIG. 37, a stent protectormeans is shown comprising a spiral sleeve 266, as shown in FIGS. 27-27aand 31 a-i. In the embodiment shown in FIG. 38 a stent protector meansis shown which comprises an inner sleeve 228 which is a spiral sleeve266 as shown at FIGS. 27, 27 a and 31 a-i, and an outer sleeve 240 ofthe type shown at FIGS. 28a-c and 29. The embodiment shown at FIG. 39shows a stent protector means comprising an inner sleeve of the typehaving a longitudinal slit 237, as shown at FIGS. 26 and 30 and an outersleeve which is a spiral sleeve 266 as shown at FIGS. 27, 27 a and 31a-i. The embodiment shown at FIG. 40 is a single sleeve stent protectorof the type shown at FIGS. 26 and 39, which has a longitudinal slit 237.FIG. 41 shows an embodiment of a stent protector having an inner sleeveof the type shown at FIGS. 26 and 30, having a longitudinal slit 237 andan outer sleeve of the type shown at FIGS. 28a-c and 29. FIG. 42 shows astent protector having an inner sleeve which is a spiral sleeve 266 asshown in FIGS. 27, 27 a and 31 a-i, and an outer sleeve having alongitudinal slit 237 as shown in FIGS. 26 and 30.

FIGS. 46-48 are side partial section views of alternative embodiments ofa single sleeve balloon or stent protector, indicated generally at 326,having a proximal end 328, a distal end 330, a continuous tubular region332 and a spiral cut region 334 having a helical slit 336 therein. Theembodiments shown at FIGS. 46-48 are all single sleeve balloonprotectors, each having a flare 338 at its proximal end 328, a helicalslit 336 defining proximal spiral cut region 334, and a continuoustubular distal region 332. As shown at FIGS. 46-47, the tubular distalregion 332 will extend proximally from the distal end 330 of the balloonprotector 326 to the position of the balloon protector which covers thedistal end of the most distal marker band, said distal marker band beinglocated interior of balloon 322 and exterior of inner lumen 315 ofcatheter 312. The embodiment shown at FIG. 46 has a relatively shorterdistal tubular region than that of the embodiment shown at FIG. 47. Thelength of the continuous tubular region will depend on the placement ofthe most distal marker band 317. As shown in FIG. 48, the proximal endof the distal tubular region may be located at any position from X to Y.

Referring now to FIGS. 49-55, an alternative embodiment of a ballooncatheter having a balloon protector according to the present inventionis shown. FIG. 49 is a longitudinal section view of the distal portionof a balloon catheter with a balloon protector according to the presentinvention, wherein the distal portion of the catheter thereof is inschematic longitudinal section view with a space between the balloon andballoon protector to show detail. The balloon protector actually closelysurrounds the balloon. Balloon 422 is a folded or wrapped balloon andthe balloon protector 440 as shown is a single sleeve. Although anysuitable sleeve according to the present invention may be used, thesleeve shown corresponds to those shown in FIGS. 50-53.

As shown at FIG. 49, catheter 412 has a shaft 413, a proximal portion(not shown) and a distal portion, indicated generally at 416. Distalportion 416 is fixed to catheter 412 by standard means known in the art.For instance, distal portion 416 may be bonded at its ends by adhesiveto the catheter in an integral manner, or may be made one-piece with thecatheter as is known in the art. Distal end portion 416 comprisesballoon 422, having a proximal end 423 and a distal end 425, balloon 422being shown in a wrapped configuration around inner 427. At its proximalend 423, balloon 422 closely surrounds distal outer 429 at its distalend 43 1. Balloon 422 is constructed and arranged for expansion from acontracted state to an expanded state. Single sleeve balloon protector426 has a proximal end 428, a distal end 430, and a dimpled region 440.This balloon protector may be of uniform diameter throughout its length,or tapered such that its diameter at distal end 430 is less than itsdiameter at proximal end 428. Balloon protector 426 will closelysurround balloon 422.

FIGS. 50-53 are views of alternative embodiments of a single sleeveballoon or stent protector, indicated generally at 426, having aproximal end 428, a distal end 430, a continuous tubular region 432 anda spiral cut region 434 having a helical slit 436 therein. Each of thesingle sleeve balloon protectors shown at FIGS. 50-53 has a flare 438 atits proximal end 428, a helical slit 436 defining proximal spiral cutregion 434, and a continuous tubular distal region 432. The inventiveballoon protector as shown may optionally be provided without a proximalflare.

FIG. 50 is a perspective view of a single sleeve balloon protectoraccording to the present invention, the balloon protector having ahelical slit therein defining a spiral cut region, and a continuoustubular region further comprising a dimpled region 440 and a straight,smooth tubular region 442. FIG. 51 is a side cross sectional view of theballoon protector of FIG. 50.

FIG. 52 is a perspective view of a single sleeve balloon protectoraccording to the present invention, the balloon protector having ahelical slit therein defining a spiral cut region, and a continuoustubular region further comprising a dimpled region 440 that is a spiraldimpled region, and a smooth, straight tubular region 442. FIG. 53 is aside cross sectional view of the balloon protector of FIG. 52.

Alternatively, the balloon protector of the present invention maycomprise a continuous tube having a spiral dimpled region 440 extendingalong part of its length, and a straight, smooth tubular region 442extending along the remaining length as shown in FIGS. 54-55, or aspiral dimpled region 440 extending along its entire length, as shown inFIG. 56. The balloon protectors shown in FIGS. 54-56 may optionally beprovided with a proximal flare as shown.

The balloon protector may be dimpled using a heat source. The dimplesmay be round-like, round or golf-ball like, spiral, triangular, oblong,longitudinal, circular (like tire treads) around the circumference or atan angle to the circumference, or combinations thereof. The dimples mayalso be of any other suitable configuration. Portions of the balloonprotector may be “dimpled”, as shown in FIGS. 50-55, or the entireballoon protector may be dimpled as shown in FIG. 56. The dimples may beprovided on a partial length of the balloon protector, one quarter toone half the length, for example, or along the fully length of theballoon protector. The dimples are generally not placed in areascorresponding to where marker bands are located.

The dimpling disclosed herein is an advantageous feature as it works thefold of the balloon and operates to break down fold edges, allowingsmaller balloon protectors to fit over balloons. This yields reducedprofiles and enables the catheter to track better and to better crosslesions.

Where a balloon protector is altered by the forming of multiple dimplesin the material thereof, the dimples deform the inner diameter as wellas the outer diameter and exterior surface. This is apparent in thecross sectional views. Dimples as disclosed herein may be formed onstraight or tapered balloon protectors or in conjunction with a curvedor bent product mandrel and any wrap style including “S”, “trifold”, orany fold such as quad, fix or six fold, for example.

The dimpled feature of the balloon protector, whether the dimples arespiral dimples or round, golf-ball-like dimples, will not only work theballoon cone down when sliding it over the balloon but will also workthe balloon while it is removed, thereby enhancing profile reduction.The balloon protector may be twisted on or pushed on. Application bytwisting on may lessen proximal bunching of the balloon.

This single sleeve balloon protector is a “one size fits all” which willaccommodate all balloons, with or without stents in a deliveryconfiguration. The advantage provided by this configuration is that itprovides a “better squeeze” or higher externally applied compressiveforce than previous press-fit balloon protectors in the art. Thisconfiguration provides a compressive force that is variable along thelength of the device, thereby providing a uniform compression amountalong the entire length of a device which may or may not have a variablediameter. This balloon protector is easier to apply to a balloon thanprevious balloon protectors known in the art. Since the collapse columnstrength and friction forces are taken out of the assembly process, theproduction yield associated with catheters employing this balloonprotector is improved.

Non limiting examples of suitable materials of which the single sleeveballoon or stent protectors of the present invention can be made arePTFE or LDPE. Other suitable materials are generally known in the artand include non-compliant, semi-compliant and compliant materials suchas polyethylene (PE), nylon, polyether block amides (PEBAX),polyethylene terephthalate (PET), silicone, POC and the like. Inaddition, the balloon and stent protectors of the present inventioncould be made of amnitel resin, such as Amnitel EM 740 sold by DSMEngineering Plastics, as set forth in U.S. Pat. No. 5,556,383,incorporated herein by reference. In addition any sleeve set forthherein which may be made of a polymeric material may be made of one ofthese materials.

The above Examples and disclosure are intended to be illustrative andnot exhaustive. These examples and description will suggest manyvariations and alternatives to one of ordinary skill in this art. Allthese alternatives and variations are intended to be included within thescope of the attached claims. Those familiar with the art may recognizeother equivalents to the specific embodiments described herein whichequivalents are also intended to be encompassed by the claims attachedhereto.

What is claimed is as follows:
 1. A medical device comprising: acatheter comprising a proximal portion, a distal portion, a shaft and anexpandable member located at the distal portion, said expandable memberbeing constructed and arranged for expanding the outer diameter of saidcatheter from a contracted state to an expanded state; and protectormeans comprising a removable sleeve formed from a shape memory material,said sleeve being positioned around the expandable member, said sleevecomprising a first end and a second end and having a variable innerdiameter by having a slit extending therethrough and from compressiveforces generated by said shape memory material.
 2. The medical device ofclaim 1 wherein the expandable member comprises a balloon and the distalportion further comprises at least one dam.
 3. The medical device ofclaim 1 wherein the sleeve comprises a straight tube.
 4. The medicaldevice of claim 1 wherein the first end of the sleeve further comprisesa proximal flare.
 5. The medical device of claim 1 wherein the slit is alongitudinal slit extending from the first end of the sleeve to thesecond end of the sleeve.
 6. A medical device comprising: a cathetercomprising a proximal portion, a distal portion, a shaft and anexpandable member located at the distal portion, said expandable memberbeing constructed and arranged for expanding the outer diameter of saidcatheter from a contracted state to an expanded state; and protectormeans comprising a removable sleeve positioned around the expandablemember, said sleeve comprising a first end and a second end and having avariable inner diameter, said sleeve comprising a straight tube andwherein at least a portion of the sleeve is dimpled.
 7. The medicaldevice of claim 6 wherein the dimples are round-like.
 8. The medicaldevice of claim 6 wherein the dimples are helical grooves.
 9. A medicaldevice comprising: a catheter comprising a proximal portion, a distalportion, a shaft and an expandable member located at the distal portion,said expandable member being constructed and arranged for expanding theouter diameter of said catheter from a contracted state to an expandedstate; and protector means comprising a removable sleeve positionedaround the expandable member, said sleeve comprising a first end and asecond end and having a variable inner diameter, said sleeve comprisinga straight tube and wherein the entire sleeve is dimpled.
 10. A medicaldevice comprising: a catheter comprising a proximal portion, a distalportion, a shaft and an expandable member located at the distal portion,said expandable member being constructed and arranged for expanding theouter diameter of said catheter from a contracted state to an expandedstate; and protector means comprising a removable sleeve positionedaround the expandable member, said sleeve comprising a first end and asecond end and having a variable inner diameter, said sleeve having aslit extending therethrough, wherein the slit is a spiral slit extendingin a helical manner from the first end of the sleeve to the second endof the sleeve and said sleeve is formed from a shape memory material toprovide said variable inner diameter.
 11. A medical device comprising: acatheter comprising a proximal portion, a distal portion, a shaft and anexpandable member located at the distal portion, said expandable memberbeing constructed and arranged for expanding the outer diameter of saidcatheter from a contracted state to an expanded state; and protectormeans comprising a removable sleeve positioned around the expandablemember, said sleeve comprising a first end and a second end and having avariable inner diameter, said sleeve having a slit extendingtherethrough, wherein the slit extends distally in a helical manner fromthe first end of the sleeve and defines a proximal spiral region, saidsleeve further comprising a distal continuous tubular portion.
 12. Themedical device of claim 11 wherein the distal continuous tubular portionfurther comprises a dimpled region and a substantially smooth region.13. The medical device of claim 12 wherein the dimples are round-like.14. The medical device of claim 12 wherein the dimples are helicalgrooves.
 15. The medical device of claim 11 wherein the first end of thesleeve further comprises a proximal flare.
 16. A medical devicecomprising: a catheter comprising a proximal portion, a distal portion,a shaft and an expandable member located at the distal portion, saidexpandable member being constructed and arranged for expanding the outerdiameter of said catheter from a contracted state to an expanded state;and removable protector means comprising: a first removable inner sleevepositioned around the expandable member, said sleeve comprising a firstend and a second end and having a variable inner diameter; a secondremovable outer sleeve positioned over the first sleeve, said secondsleeve having a first end and a second end, said first and secondsleeves being removed prior to use of the medical device.
 17. Themedical device of claim 16 wherein the expandable member and the firstsleeve are of a material which resiliently deforms under radialpressure.
 18. The medical device of claim 16 wherein the first sleeveand the second sleeve are made of a low friction material.
 19. Themedical device of claim 16 wherein at least one of said first and secondsleeves is a straight or continuous tube.
 20. A medical devicecomprising: a catheter comprising a proximal portion, a distal portion,a shaft and an expandable member located at the distal portion, saidexpandable member being constructed and arranged for expanding the outerdiameter of said catheter from a contracted state to an expanded state;and removable protector means comprising: a first removable inner sleevepositioned around the expandable member, said sleve comprising a firstend and a second end and having a variable inner diamete; a secondremovable outer sleeve positioned over the first sleeve, said secondsleeve having a first end and a second end, said first and secondsleeves being removed prior to use of the medical device, wherein saidfirst sleeve is coextruded and has a high friction inner diameter and alow friction outer diameter, whereby the inner sleeve will not slip whenthe outer sleeve is pushed thereon.
 21. A medical device comprising: acatheter comprising a proximal portion, a distal portion, a shaft and anexpandable member located at the distal portion, said expandable memberbeing constructed and arranged for expanding the outer diameter of saidcatheter from a contracted state to an expanded state; and removableprotector means comprising: a first removable inner sleeve positionedaround the expandable member, said sleeve comprising a first end and asecond end and having a variable inner diameter; a second removableouter sleeve positioned over the first sleeve, said second sleeve havinga first end and a second end, said first and second sleeves beingremoved prior to use of the medical device, wherein at least one of saidfirst and second sleeves is a straight or continuous tube and wherein atleast a protion of said atleast one continuous tube is dimpled.
 22. Themedical device of claim 21 wherein the continuous tube has round-likedimples.
 23. The medical device of claim 21 wherein the continuous tubehas helical grooved dimples.
 24. The stent delivery system of claim 21wherein the entire continuous tube is dimpled.
 25. A medical devicecomprising: a catheter comprising a proximal portion, a distal portion,a shaft and an expandable member located at the distal portion, saidexpandable member being constructed and arranged for expanding the outerdiameter of said catheter from a contracted state to an expanded state;and removable protector means comprising: a first removable inner sleevepositioned around the expandable member, said sleeve comprising a firstend and a second end and having a variable inner diameter; a secondremovable outer sleeve positioned over the first sleeve, said secondsleeve having a first end and a second end, said first and secondsleeves being removed prior to use of the medical device, and wherein atleast one of said and second sleeves has a slit extending therethrough.26. The medical device of claim 25 wherein the slit is a longitudinalslit extending from the first end of the sleeve to the second end of thesleeve.
 27. The medical device of claim 25 wherein the slit is a spiralslit extending in a helical manner from the first end of the sleeve tothe second end of the sleeve.
 28. The medical device of claim 25 whereinthe slit extends distally in a helical manner from the first end of thesleeve and defines a proximal spiral region, said sleeve furthercomprising a distal continuous tubular portion.
 29. The medical deviceof claim 28 wherein the distal continuous tubular portion furthercomprises a dimpled region and a substantially smooth region.
 30. Themedical device of claim 29 wherein the dimples are round-like.
 31. Themedical device of claim 29 wherein the dimples are helical grooves. 32.A medical device comprising: a catheter comprising a proximal portion, adistal portion, a shaft and an expandable member located at the distalportion, said expandable member being constructed and arranged forexpanding the outer diameter of said catheter from a contracted state toan expanded state; and removable protector means comprising: a firstremovable inner sleeve positioned around the expandable member, saidsleeve comprising a first end and a second end and having a variableinner diameter; a second removable outer sleeve positioned over thefirst sleeve, said second sleeve having a first end and a second end,said first and second sleeves being removed prior to use of the medicaldevice, and wherein the distal portion of the cather further comprisesat least one enlarged portion, whereby when compressed by the outersleeve, the inner sleeve will have an inner diameter less than or equalto the outer diameter of the at least one enlarged portion.
 33. Themedical device of claim 32 wherein the at least one enlarged portioncomprises a proximal dam and a distal dam spaced a predetermineddistance apart, said dams having an equal outer diameter, and theexpandable member comprises a balloon located over and between saiddams.